The invention relates to wireless telecommunications, and, more particularly, to voice mail retrieval from a roaming mobile station.
The use of mobile telecommunications systems, including cellular telephones and personal communications services (PCS), has seen explosive growth, particularly in the past decade. The use of mobile, or cellular, telephones has become so commonplace that it is not unusual to see people conversing on the telephone as they walk along the sidewalk, as they drive, as they sit poolside, or as they attend a sporting event. There is a very real need being met by mobile systems. However unfortunate it may be, people tend to work longer hours now and are under a great deal of pressure to xe2x80x9cmulti-taskxe2x80x9d as much as possible. Mobile telecommunications systems allow them to do this.
A mobile telecommunications subscriber who xe2x80x9croamsxe2x80x9d, that is, travels outside his home service area, may wish to access his xe2x80x9cvoice mailxe2x80x9d as he travels. One approach to providing access to a user""s voice mail is to employ a special xe2x80x9cstar codexe2x80x9d feature, that is, a feature which requires a user to key in a special series of digits on his mobile station. One example of such codes is the familiar star 69 (*69), which provides the user with the directory number of the most recent incoming call. Remembering the various star code digit sequences can be a frustrating, inconvenient, and confusing task. To avoid the confusion and frustration associated with the star code approach some telecommunications systems allow a roaming user to dial his own directory number. The system attempts to deliver the call, but, since the mobile station is outside the range of its home mobile switching center (MSC), the call cannot be completed. After the call fails, the system establishes a default connection to the user""s message recording service, at which point the subscriber may access his recorded messages. Although it has the benefit of obviating the use of special star code sequences, this is an awkward, time-consuming approach which anyone who has been forced to listen through several tiers of selections offered by an automated call distribution system will recognize as an incredibly frustrating experience. Additionally, this approach consumes telephone system resources that might otherwise be put to better use.
Systems which employ xe2x80x9cOriginationRequestxe2x80x9d invocations to allow a subscriber to access his voice mail as he roams have been proposed. Such systems are discussed, for example, in TIA/EIA SP-3588, which is hereby incorporated by reference. Although such an approach may be effective for new systems, a huge installed base of telephony equipment does not support such an approach. A system that provides greater flexibility in providing access to voice mail, one which provides other means of access to voice mail for a roaming subscriber, would be highly desirable.
A mobile switching center (MSC) in accordance with the principles of the present invention provides access to a subscriber""s voice mail message from the subscriber""s roaming mobile station. The MSC is responsive to a xe2x80x9cRemoteFeatureRequestxe2x80x9d invocation by the roaming mobile station in which the subscriber""s directory number is the same as the dialed digits by routing the call from the mobile station to the subscriber""s voice mail. The MSC may also be responsive to a xe2x80x9cOriginationRequestxe2x80x9d employing the subscriber""s directory number as the dialed digits by routing the roaming mobile station""s call to the subscriber""s voice mail system. If the MSC supports both RemoteFeatureRequest-, and OriginationRequest-based access to the subscriber""s voice mail, the MSC determines which of the approaches to use in response to the reception of a subscriber""s directory number as the dialed digits from the subscriber""s roaming mobile station. The MSC may make this determination on the basis of information stored in a local database that indicates the method employed by other telecommunications devices, such as other MSCs, Visiting Location Registers, or Home Location Registers, within the system. One of the methods, that is, the use of an OriginationRequest invocation or the use of a RemoteFeatureRequest invocation, may be chosen as a default method.